One of micro-fabrication techniques is a nanoimprint technique in which a plate-like or a cylindrical (columnar) master on which surface a fine pattern is formed is pressed against a resin sheet for example to transfer the fine pattern on the master to the resin sheet for example.
JP 2015-005678 A (PTL 1) discloses an exposure apparatus for forming a fine pattern on a surface of a master. This exposure apparatus includes spindles provided at both ends of a cylindrical master to hold the master between them, and a light source emitting a laser beam (laser light). While the master of which surface is coated with thermo-reactive resist or photoreactive resist is rotated, the master is irradiated with (subjected to) a laser beam emitted from the light source in a pattern corresponding to a desired pattern, so that the thermo-reactive resist or photoreactive resist is reacted to form the desired pattern on the surface of the master. Further, the exposure apparatus receives the laser beam reflected by the master with a four-quadrant detector having an active area with four separate receiving areas and controls the focal position of the laser beam depending on the received light.